Need:
(at least) 1x Ball Bearing (9.5 mm or 3/8 inch) But other sizes will work too. If the ball is too light it may not work (No ball smaller than a 1/4 in or 6.35 mm)

My friend gave me the idea to design a circular die. You can print this in TPU if you want it to be bouncy.

No supports in the center of the ball. Support the outside of the bottom hemisphere. Refer to Cura example (Last Picture). Slip a Ball Bearing in midway through the print.

I uploaded the Solidworks 2021 file here as well. Happy Rolling.